U.S. patent application number 13/607783 was filed with the patent office on 2013-09-12 for self-closing devices and methods for making and using them.
This patent application is currently assigned to Solinas Medical Inc.. The applicant listed for this patent is Michael J. Drews, James HONG. Invention is credited to Michael J. Drews, James HONG.
Application Number | 20130237929 13/607783 |
Document ID | / |
Family ID | 44564106 |
Filed Date | 2013-09-12 |
United States Patent
Application |
20130237929 |
Kind Code |
A1 |
HONG; James ; et
al. |
September 12, 2013 |
SELF-CLOSING DEVICES AND METHODS FOR MAKING AND USING THEM
Abstract
A self-closing device for implantation within a patient's body
includes base material including an inner surface area for securing
the base material to a tissue structure, and a plurality of support
elements surrounding or embedded in the base material. The support
elements are separable laterally within a plane of the base
material to accommodate creating an opening through the base
material for receiving one or more instruments through the base
material, and biased to return laterally towards a relaxed state
for self-closing the opening after removing the one or more
instruments. The device may be provided as a patch or integrally
attached to a tubular graft or in various shapes.
Inventors: |
HONG; James; (Sunnyvale,
CA) ; Drews; Michael J.; (Palo Alto, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONG; James
Drews; Michael J. |
Sunnyvale
Palo Alto |
CA
CA |
US
US |
|
|
Assignee: |
Solinas Medical Inc.
Sunnyvale
CA
|
Family ID: |
44564106 |
Appl. No.: |
13/607783 |
Filed: |
September 9, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/US2011/027796 |
Mar 9, 2012 |
|
|
|
13607783 |
|
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Current U.S.
Class: |
604/264 |
Current CPC
Class: |
A61B 2017/00862
20130101; A61B 2017/00867 20130101; A61M 2039/0258 20130101; A61B
17/0057 20130101; A61M 2039/0291 20130101; A61B 2017/00676
20130101; A61B 2090/3966 20160201; A61B 2017/1107 20130101; A61B
2017/12004 20130101; A61B 2017/00876 20130101; A61M 2039/0261
20130101; A61B 17/3403 20130101; A61F 2/064 20130101; A61B 17/11
20130101; A61M 39/0247 20130101; A61B 2017/00597 20130101; A61B
2017/1135 20130101; A61F 2210/009 20130101; A61M 1/3655 20130101;
A61B 90/39 20160201; A61B 2017/00592 20130101; A61B 2090/3962
20160201 |
Class at
Publication: |
604/264 |
International
Class: |
A61M 25/00 20060101
A61M025/00 |
Claims
1. An access port for a tubular structure within a patient's body,
comprising: a port body comprising a first end, a second end, a
longitudinal axis extending therebetween, and a wall including
inner and outer surfaces extending between the first and second
ends and defining opposite side edges extending between the first
and second ends; and a plurality of bands embedded in or
surrounding the port body, each band comprising a plurality of
struts including spaces therebetween, the struts being separable
laterally within a plane of the wall to create a passage through
the port body to accommodate an instrument being introduced
therethrough the port body and resiliently biased to return
laterally when the instrument is removed to substantially close the
passage.
2-4. (canceled)
5. The access port of claim 1, wherein the port body comprises a
"C" shaped cross-section extending between the first and second
ends.
6-8. (canceled)
9. The access port of claim 1, wherein the bands impose a
substantially continuous compressive force on the base material to
enhance sealing a passage created through the port body.
10. The access port of claim 1, wherein the struts extend at least
one of substantially perpendicular to the longitudinal axis,
substantially parallel to the longitudinal axis, and helically
relative to the longitudinal axis.
11. An access port attachable to a surface within a patient's body,
comprising: a port body comprising flexible base material defining
a first end, a second end, a longitudinal axis extending
therebetween, and a wall including inner and outer surfaces
extending between the first and second ends; and a plurality of
elastic elements embedded in or surrounding the port body, the
elastic elements being separable to create a passage through the
port body to accommodate an instrument being introduced
therethrough the port body and resiliently biased to substantially
close the passage.
12. The access port of claim 11, wherein the elastic elements
impose a substantially continuous compressive force on the base
material to enhance sealing a passage created through the port
body.
13-14. (canceled)
15. The access port of claim 11, wherein the elastic elements
comprise a plurality of struts disposed adjacent one another in a
relatively low energy state, the struts being separable to create a
passage through the port body between struts to accommodate an
instrument being introduced therethrough the port body, thereby
directing the struts to a relatively high energy state, such that,
when the instrument is removed, the struts are biased to return
towards the relatively low energy state to substantially close the
passage.
16. The access port of claim 15, wherein the struts extend at least
one of substantially perpendicular to the longitudinal axis,
substantially parallel to the longitudinal axis, and helically
relative to the longitudinal axis.
17. The access port of claim 11, wherein the port body is biased to
a curved configuration extending between the first and second
ends.
18. The access port of claim 11, wherein the port body is
substantially flat.
19-27. (canceled)
28. The access port of claim 11, further comprising one or more
elements for facilitating locating the access port through a
patient's skin.
29-35. (canceled)
36. A method for implanting an access port into a patient's body,
comprising: exposing a body structure within a patient's body; and
attaching an access port to the outer surface of the body
structure, the access port comprising base material and a plurality
of support elements, the support elements separable laterally to
accommodate creating an opening through the base material for
receiving one or more instruments through the base material, and
biased to return laterally towards a relaxed state for self-closing
the opening after removing the one or more instruments.
37. The method of claim 36, wherein the body structure comprises a
tubular structure.
38. The method of claim 37, wherein attaching the access port to a
body structure comprises: separating side edges of the access port
to open the access port; positioning the access port adjacent the
tubular structure; and releasing the side edges such that the
access port wraps at least partially around the tubular
structure.
39-40. (canceled)
41. The method of claim 36, wherein attaching the access port to a
body structure further comprises securing the access port to the
body structure by at least one of bonding with adhesive and
suturing the access port to the body structure.
42. The method of claim 36, wherein the body structure comprises at
least one of a tubular graft, a fistula, and a blood vessel.
43. The method of claim 36, further comprising: inserting one or
more instruments through the access port into the body structure,
the support elements separating to create a passage through the
base material, the support elements resiliently biased to compress
the base material to close the passage after the one or more
instruments are removed from the access port.
44. The method of claim 43, further comprising identifying the
access port by palpation before inserting the one or more
instruments.
44-49. (canceled)
50. An implantable graft, comprising: an elongate tubular graft
including first and second ends and a graft lumen extending
therebetween; and an access port attached to a sidewall of the
tubular member, the access port comprising flexible base material
and a plurality of elastic elements embedded in or surrounding the
flexible base material, the elastic elements being separable to
create a passage through the access port to accommodate an
instrument being introduced through the access port into the graft
lumen and resiliently biased to substantially close the
passage.
51. (canceled)
52. A method for accessing a lumen of a body structure within a
patient's body, comprising: implanting an access port on a surface
of the body structure; inserting one or more instruments through
the patient's skin and the access port into the lumen of the body
structure, thereby creating an access passage through the body
structure; and performing a procedure within the patient's body via
the lumen; and removing the one or more instruments from the access
port, whereupon the access port resiliently closes inwardly to
substantially seal the access passage.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation-in-part of co-pending
International Application No. PCT/US2011/027796, filed Mar. 9,
2012, which claims benefit of co-pending provisional application
Ser. No. 61/312,183, filed Mar. 9, 2010, and 61/385,483, filed Sep.
22, 2010, the entire disclosures of which are expressly
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The field of the invention generally relates to self-closing
devices that are implantable within a patient's body and to
apparatus, systems, and methods including such self-closing
devices. For example, the present invention may include
self-closing tubular structures, cuffs, or patches, and/or grafts
that include resealable access ports or regions including
self-closing tubular structures, and/or may include systems and
methods for implanting such self-closing structures and/or
grafts.
BACKGROUND
[0003] Dialysis for end stage renal disease ("ESRD") is one of the
leading and rapidly growing problems facing the world today. In
2006, there were greater than fifty one million (51,000,000) people
in the United States diagnosed with chronic kidney disease. Greater
than five hundred thousand (500,000) people in this population
suffered from ESRD. With the growing aging population and
increasing prevalence of high risk factors such as diabetes (35% of
all ESRD patients, Szycher M., J Biomater Appl. 1999; 13, 297-350)
and hypertension (30%), the projected population in 2020 is greater
than 784,000 (est. USRDS 2008).
[0004] The two primary modes of treatment are kidney transplant and
hemodialysis. Due to the shortage of available transplant kidneys,
approximately seventy percent (70%) of people with ESRD undergo
hemodialysis (USRDS 2008) for life or until a transplant kidney
becomes available. To facilitate the frequent, periodic treatments,
patients must undergo vascular surgery to prepare their artery and
vein, typically in their forearm, for dialysis. The two most common
methods of preparing the artery and vein are arteriovenous (AV)
fistulas and AV grafts--the former is the preferred option due to
longer patency rates; however fistulas are often replaced by AV
grafts once the life of the fistula has been exhausted.
[0005] There are advantages and disadvantages to both methods. Most
notably, grafts are easy to implant, and ready to use relatively
sooner, but have shorter lifespans and are more prone to infection
and thrombus formation. Fistulas have greater durability and are
less prone to infection, but can take up to six (6) months (KDOQI)
to mature before use, and the veins used for access have tendencies
to develop pseudo-aneurysms at the site of repeated access. One of
the contributing factors to the rapid degradation of current AV
grafts and/or veins is the repeated needle sticks during dialysis
with relatively large needles (e.g., 14-16 Gauge). This is
exacerbated because the average patient undergoes hemodialysis
treatment two or three times a week, every week of every year until
a kidney replacement is available or until the end of their life
expectancy, which is approximately ten (10) years (Szycher M., J
Biomater Appl. 1999; 13, 297-350). Moreover, due to the high risk
of intimal hyperplasia and vessel narrowing, dialysis patients also
undergo periodic interventional treatment to maintain patent
vessels, which may occur several times a year. This typically
involves angioplasty or stenting, akin to the treatment of coronary
vascular occlusions, and vascular access using needles is also
needed for these procedures, thereby contributing to the risk of
graft or vessel degradation.
[0006] Therefore, there is an apparent need for devices, systems,
and methods for treating ESRD and other conditions.
SUMMARY
[0007] The present application generally relates to self-closing
devices that are implantable within a patient's body and to
apparatus, systems, and methods including such self-closing
devices. For example, apparatus, systems, and methods described
herein may include self-closing tubular structures, cuffs, or
patches, and/or grafts that include resealable access ports or
regions including self-closing structures.
[0008] In accordance with an exemplary embodiment, a Circular
Elastic Band ("CEB") may be provided that is made of a
biocompatible material with design features suitable for multiple
clinical applications. In general, the CEB may be expanded radially
outwardly and, when released, may elastically return radially
inwardly towards its original shape while compressing material
contained within its inner diameter. The CEB may be used, for
example, in one or more of the following applications to close an
opening in the wall(s) of a tubular structure or tissue wall while
facilitating repeated re-access and re-closure, or restrict (or
prevent) and control material flow through a tubular structure:
facilitating repeated re-access in an arteriovenous (AV) vascular
grafts for hemodialysis; closing a vascular opening in a vessel
wall after an endovascular procedure; or closing patent foramen
ovale (PFO closure).
[0009] For example, in applications where a pressure gradient may
exist across the CEB, the strength of the closure may be sufficient
to prevent leakage.
[0010] In accordance with another embodiment, a self-sealing access
device is provided that includes base material, e.g., elastomeric
and/or bioabsorbable material, including a surface area for
securing the base material to a tissue structure; and a plurality
of support elements surrounding or embedded in the base material.
The support elements may be separable to accommodate creating an
opening through the base material for receiving one or more
instruments through the base material, and biased to return towards
a relaxed state for self-closing the opening after removing the one
or more instruments. In exemplary embodiments, the device may be a
cuff, a patch, or other device that may be secured around or to a
tubular, curved, or substantially flat body structure.
[0011] For example, the support elements may include a plurality of
struts spaced apart from one another to define openings in a
relaxed or relatively low stress state. The struts may be separable
from one another, e.g., to a relatively high stress state, to
accommodate receiving one or more instruments through the openings
and the base material filling or adjacent to the openings, the
struts resiliently biased to return towards one another, e.g., to
the relaxed or relatively low stress state.
[0012] In accordance with still another embodiment, a method is
provided for implanting an access port into a patient's body that
includes exposing a tubular body or other surface within a
patient's body, e.g., a curved or substantially flat surface of a
tubular body or other tissue structure, such as a vessel or graft,
a heart, or a wall of the abdomen; and attaching an access port to
the outer surface of the tubular body or tissue structure. The
access port may include base material and a plurality of support
elements, the support elements separable to accommodate creating an
opening through the base material for receiving one or more
instruments through the base material, and biased to return towards
a relaxed or relatively low stress state for self-closing the
opening after removing the one or more instruments.
[0013] In accordance with yet another embodiment, a system or kit
is provided for accessing a tissue structure or graft implanted
within a patient's body that includes a self-closing access device
and an instrument for providing access through the access device.
For example, the access device may include a cuff or patch that may
be attached to the tissue structure or graft, e.g., including base
material, e.g., elastomeric and/or bioabsorbable material, and a
plurality of support elements surrounding or embedded in the base
material.
[0014] In an exemplary embodiment, the instrument may be a needle
including a tip insertable through the base material between one or
more of the support elements. The tip of the needle may be
configured to facilitate passing the needle between the support
elements, e.g., including at least one of a coating, a surface
treatment, and the like, to facilitate passing the needle between
the support elements. In addition, the tip may be beveled or
tapered, e.g., including a beveled shape, to facilitate inserting
the needle through the base material between the support elements.
Optionally, the support elements may be configured to facilitate
inserting the needle therethrough, e.g., including tapered or
rounded edges.
[0015] In addition or alternatively, the instrument may include one
or more features for limiting the depth of penetration of the tip
through the access device. For example, the needle may include a
bumper spaced apart a predetermined distance from the tip to
prevent over-penetration of the needle through the access
device.
[0016] In accordance with still another embodiment, an implantable
graft is provided that includes an elongate tubular graft including
first and second ends and a graft lumen extending therebetween; and
an anastomotic flow coupler on the first end for coupling the graft
to a body lumen. Optionally, the graft may also include an access
port in a sidewall of the tubular member, e.g., similar to any of
the embodiments herein.
[0017] In one embodiment, the coupler may include a flexible
tubular body extending from the first end and an elastic support
structure supporting the tubular body. The support structure may
support the tubular body, e.g., to reduce kinking or buckling, or
may be biased to expand the tubular body to a first diameter, yet
may be resiliently compressible to allow insertion into a body
lumen. For example, at least a portion of the support structure may
be biased to expand the tubular body to a diameter larger than an
inner diameter of the body lumen to enhance remodeling of the body
lumen once the coupler is secured therein.
[0018] In another embodiment, the coupler may include a
self-expanding frame attached to the first end of the tubular graft
and a flared rim extending from the frame for securing the first
end relative to a body lumen. In yet another embodiment, the
coupler may include a balloon expandable frame attached to the
first end of the tubular graft, the frame being plastically
deformable to form a flared rim extending from the graft for
securing the first end relative to a body lumen. In still another
embodiment, the coupler may include a tubular mesh coupled to the
first end of the tubular graft at an intermediate location on the
tubular mesh between open ends such that the graft lumen
communicates with an interior of the tubular mesh. In another
embodiment, the coupler may include a self-expanding frame attached
to the first end of the tubular graft and a tubular mesh coupled to
the frame at an intermediate location on the tubular mesh.
[0019] In accordance with yet another embodiment, an access port is
provided for a tubular structure within a patient's body that
includes a port body including a first end, a second end, and a
wall extending between the first and second ends defining side
edges extending between the first and second ends, e.g.,
substantially parallel to a longitudinal axis, and a plurality of
bands embedded in or surrounding the port body. Each band may
include a plurality of struts including spaces therebetween, the
struts being separable to create a passage through the port body to
accommodate an instrument being introduced therethrough the port
body and resiliently biased to compress the port body to close the
passage.
[0020] In one embodiment, the port body may be a patch, optionally,
including a sewing ring around its periphery. Alternatively, the
port body may be a cuff or an enclosed tubular body.
[0021] In accordance with still another embodiment, a method is
provided for accessing a body structure within a patient's body
that includes providing an access port comprising a port body
including a first end, a second end, and a wall extending between
the first and second ends defining side edges extending between the
first and second ends, e.g., substantially parallel to a
longitudinal axis, and a plurality of bands embedded in or
surrounding the port body, each band comprising a plurality of
struts defining a zigzag pattern; the method further including
attaching the port body to a body structure. In exemplary
embodiments, the port body may be a tubular body, a "C" shaped body
or other cuff, or a patch, e.g., having a curved, flat, conical, or
other shape. Thereafter, one or more instruments may be inserted
through the port body into the body structure, the struts of the
bands separating to create a passage through the port body. The
bands may be resiliently biased to compress the port body or
otherwise return towards their original configuration to close the
passage after the one or more instruments are removed from the port
body.
[0022] In accordance with yet another embodiment, an access port is
provided for a tubular structure within a patient's body that
includes a port body including a first end, a second end, and a
wall extending between the first and second ends defining side
edges extending between the first and second ends, e.g.,
substantially parallel to a longitudinal axis; and a side port
extending transversely from the port body. A band may be embedded
in or surrounding the side port, the band including a plurality of
struts defining a zigzag pattern. The band may be expandable from a
contracted condition to an enlarged condition to accommodate
receiving one or more instruments through the side port, yet biased
to return towards the contracted condition to compress the side
port radially inwardly to seal the side port after the one or more
instruments are removed therefrom.
[0023] In accordance with another embodiment, an arteriovenous
graft system is provided that includes an elongate tubular graft
including first and second ends and a graft lumen extending
therebetween; an access port in a sidewall of the tubular member;
and a locator device. In an exemplary embodiment, the access port
may include a tubular member including first and second ends and
defining an access lumen extending between the first and second
ends. The tubular member may be expandable from a contracted
condition to an enlarged condition to allow access to the graft
lumen, yet biased to return towards the contracted condition to
substantially seal the access lumen.
[0024] In addition, the access port may include one or more locator
elements, e.g., a first plurality of ferromagnetic elements
disposed around the tubular member. The locator device may include
a proximal end, and a distal end including a second plurality of
ferromagnetic elements disposed around a passage. The second
plurality ferromagnetic elements may be disposed around the passage
in a configuration similar to the first plurality of ferromagnetic
elements such that the distal end of the locator device is
magnetically attracted to the access port such that the passage is
aligned with the access lumen of the tubular member to facilitate
introducing one or more instructions through the passage and access
lumen into the graft lumen.
[0025] In another embodiment, the locator device may include a
proximal end, a distal end including a passage therethrough for
receiving one or more instruments therethrough, and an inductance
meter on the distal end adjacent the passage for detecting when the
passage is aligned with the access lumen of the tubular member,
e.g., to facilitate introducing one or more instructions through
the passage and access lumen into the graft lumen.
[0026] Other aspects and features of the present invention will
become apparent from consideration of the following description
taken in conjunction with the accompanying drawings and
Appendices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The drawings illustrate exemplary embodiments, in which:
[0028] FIG. 1A is a top view of an exemplary embodiment of an
arteriovenous graft including self-closing access ports.
[0029] FIG. 1B is a detail of one end of the graft of FIG. 1A,
showing an anastomotic connector thereon.
[0030] FIG. 1C is a detail of the graft of FIG. 1 showing an
embedded helical spine in the graft wall.
[0031] FIGS. 1D and 1E are top and side views, respectively, of an
access port in the graft of FIG. 1A.
[0032] FIG. 2 is a perspective view of an exemplary embodiment of a
self-closing device, namely a circular elastic band ("CEB"), that
may be incorporated into an access port, such as that shown in
FIGS. 1D and 1E.
[0033] FIG. 3 is a graph showing an idealized stress-strain curve
for Nitinol material.
[0034] FIGS. 4A and 4B are side and perspective views,
respectively, of another exemplary embodiment of a self-closing
device, namely a conduit closure device ("CCD"), which,
alternatively, may be incorporated into an access port.
[0035] FIGS. 5A and 5B are side and top views, respectively, of an
exemplary embodiment of a self-closing access port and an
instrument for locating the access port.
[0036] FIG. 5C is a perspective detail of the locator instrument of
FIGS. 5A and 5B.
[0037] FIG. 6 is a detail of a distal end of an alternative
embodiment of an instrument for locating an access port, similar to
that shown in FIGS. 5A and 5B, including an antiseptic pad.
[0038] FIGS. 7A and 7B are side and end views, respectively, of a
sutureless anastomosis connector that may be provided on a tubular
graft, such as that shown in FIG. 1A.
[0039] FIG. 7C is a perspective view of an elastic frame that may
be provided on the connector of FIGS. 7A and 7B.
[0040] FIG. 8 is a side view of an alternative embodiment of a
sutureless anastomosis connector that may be provided on a tubular
graft, such as that shown in FIG. 1A.
[0041] FIG. 9A is a perspective view showing an exemplary
embodiment of a flow restrictor device that may be included in a
tubular graft, such as that shown in FIG. 1A.
[0042] FIG. 9B is an end view of the flow restrictor device of FIG.
9A.
[0043] FIGS. 9C and 9D are perspective views of the flow restrictor
device of FIGS. 9A and 9B, showing the device in open and
restrictive positions, respectively.
[0044] FIGS. 10A-10C are side, top, and end views, respectively, of
an embodiment of an access port, including a circular elastic band
("CEB") embedded in a silicone sleeve (with fabric covering not
shown), and attached to a tubular graft.
[0045] FIGS. 11A-11C are top, bottom, and end views, respectively,
of the sleeve of FIGS. 10A-10C split along a length of the sleeve
and covered with fabric to provide a cuff with integral access
port.
[0046] FIG. 11D is a bottom view of the cuff of FIGS. 11A-11C with
the cuff opened and substantially flattened.
[0047] FIGS. 12A and 12B are side and top views, respectively, of a
sleeve similar to the sleeve of FIGS. 10A-10C attached to a length
of tubing to provide an integral access port.
[0048] FIG. 13A is a side view of a silicone sleeve including a
plurality of rings including separable struts embedded therein.
[0049] FIG. 13B is a side view of the silicone sleeve of FIG. 13A
split along a length of the sleeve.
[0050] FIGS. 14A-14C are top, bottom, and end views, respectively,
of the sleeve of FIG. 13B covered with fabric to provide a cuff
with integral penetrable, self-sealing access port.
[0051] FIG. 15 is a side view of a length of silicone tubing
including a plurality of zigzag rings embedded therein.
[0052] FIGS. 16A and 16B are top and bottom views, respectively, of
a silicone sleeve created from the silicone tubing of FIG. 15,
split along its length, and attached onto a length of tubing.
[0053] FIGS. 17A and 17B are bottom and top views, respectively, of
the silicone sleeve and tubing of FIGS. 16A and 16B with the
silicone sleeve covered with fabric to provide an integral access
port.
[0054] FIG. 17C is a cross-sectional view of the access port and
tubing of FIGS. 17A and 17B, taken along lines 17C-17C.
[0055] FIG. 17D is a perspective view of an exemplary embodiment of
one of the bands that may be embedded in the silicone sleeve of
FIGS. 16A-17C.
[0056] FIG. 18 is a top view of an exemplary embodiment of a
reinforced patch including elastic support elements embedded in a
base material and surrounded by a sewing ring.
[0057] FIGS. 19A-19C are top views of a wall of a vessel, showing a
method for repairing the wall using the patch of FIG. 18.
[0058] FIGS. 20A and 20B are cross-sectional views of alternative
embodiments of cuffs being attached around a tubular body
structure.
[0059] FIG. 21 is a cross-sectional view of a tubular body
structure and a side view of one end of a tubular graft being
attached to the tubular structure such that a flexible flow coupler
on the graft extends into a lumen of the tubular structure.
[0060] FIG. 22 is a cross-sectional view of a tubular body
structure and a side view of one end of another tubular graft being
attached to the tubular structure such that a flexible flow coupler
on the graft extends into a lumen of the tubular structure.
[0061] FIG. 23 is a side view of one end of a tubular graft
including a flexible flow coupler biased to a spiral shape.
[0062] FIG. 24A is a top view of another embodiment of an access
port including a plurality of overlapping bands in adjacent
frustoconical shapes.
[0063] FIGS. 24B and 24C are side and end views of an individual
frustoconical access port member that may be included in the access
port of FIG. 24A.
[0064] FIG. 25A is a cross-section view of a tubular body structure
including the access port of FIGS. 24A-24C implanted around the
structure.
[0065] FIG. 25B is a cross-section of the tubular body structure
and access port of FIG. 25A, taken along lines 25B-25B.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0066] Turning to the drawings, FIG. 1A shows an exemplary
embodiment of an arteriovenous graft 10 that includes multiple
self-closing access ports 30, e.g., each including a circular
elastic band ("CEB") 50, e.g., as shown further in FIGS. 1D and 1E.
The CEBs 50 may be preformed within the AV graft, e.g., to provide
two ports for standard arterial and venous access, as shown.
Optionally, a plurality of ferromagnetic elements 58 may be
provided around or otherwise adjacent the CEB 50, e.g., to
facilitate identifying and/or locating the access port 30, as
described in the applications incorporated by reference herein. The
graft 10 may be fabricated from well-known synthetic or biological
material for vascular grafts, and the embedded port access (PA)
sites may be used for access and re-access during hemodialysis
using standard gauge needles, e.g., fourteen or sixteen gauge
(14G-16G) needles, through the center region of the structure.
[0067] The access port 30 may also be used during standard
angioplasty, vascular stenting, or thrombectomy procedures to
manage and maintain AV patency for dialysis. The structure of the
CEB 50 may elastically expand radially outwardly, and, upon removal
of the dialysis needle, the structure may largely return to its
original size and shape without any (or significant) permanent
deformation and create an immediate seal by compressing the
material within the structure.
[0068] The graft 10 may be surgically or percutaneously implanted
using standard techniques of making standard incisions and/or
forming suture based anastomotic junctions or unique methods of
using sutureless based anastomotic junctions. As the AV graft 10 is
implanted, the elastic structure may be strategically placed
subcutaneously for easy access. Furthermore, optionally, the CEB
subassembly (or any of the other access devices described herein)
may be augmented with features or components that may facilitate
identification of the access site(s) for the insertion of a
dialysis needle or catheterization instruments, as described
further below.
[0069] FIG. 2 shows an exemplary embodiment of a circular elastic
band or "CEB" 50 that generally includes a tubular member sized for
implantation in a patient's body, e.g., either alone or
incorporated into another device or system. FIGS. 4A and 4B show an
alternative embodiment of a CEB 50' that may be used instead of CEB
50. For example, the CEB 50 may be embedded or otherwise
incorporated into the AV graft shown in FIGS. 1A 1D, and 1E.
Alternatively, the CEB 50 may be implanted directly into tissue,
e.g., to seal a puncture or other opening through tissue, as
disclosed in the applications incorporated by reference herein.
[0070] The CEB 50 is resiliently expandable from a contracted
condition to an enlarged condition, yet biased to return towards
the contracted condition. As shown in FIG. 2, the CEB 50 includes a
plurality of struts 52 defining a serpentine pattern around a
circumference of the CEB, each strut 52 including opposing ends
that are alternately connected to adjacent struts, e.g., by curved
connectors or elements 54, to define a zigzag or other serpentine
pattern. In the contracted condition, the struts 52 may contact one
another or otherwise minimize the cross-section of a lumen 56
extending through the CEB 50, yet may become spaced apart from one
another as the CEB 50 is expanded to the enlarged condition,
thereby increasing the size of the lumen 56 extending through the
CEB 50, e.g., to accommodate receiving one or more devices or other
structures through the lumen 56. It will be appreciated that other
rings or bands may be provided for the CEB 50, e.g., a tubular mesh
band that is expandable to provide a passage through the band to
accommodate one or more instruments, yet resiliently compressible
to close the passage upon removal of the instrument(s), as
described elsewhere herein.
[0071] After the graft 10 has been implanted within a patient's
body, the access ports 30 may be used to access the interior of the
graft 10, e.g., during hemodialysis. Optionally, a locator device
60 may be used to identify and/or locate the access port 30 to
facilitate insertion of a dialysis needle or introducer needle for
an endovascular catheterization procedure. For example, each access
port 30 may include a plurality of markers, e.g., ferromagnetic,
echogenic, or other elements 58, e.g., surrounding or otherwise
adjacent the access port 30. As shown in FIG. 1D, three magnetic
elements 58 are shown spaced apart and surrounding the CEB 50.
[0072] As shown in FIGS. 5A-5C, the locator device 60 may include a
similar arrangement of ferromagnetic elements 62 that may
correspond to the elements 58 in the access port 50. In addition,
the locator device 60 may include an alignment hole 64 surrounded
by the elements 62, e.g., to guide a needle or other instrument
(not shown) through the access port 30, as described in the
applications incorporated by reference herein. For example, the
elements 58, 62 may guide the locator device 60 to align the hole
64 with the CEB 50, thereby facilitating inserting a needle through
the hole 64 and the CEB 50 into the graft 10. Alternatively, the
locator device 60 may include an inductance meter or other sensor
(not shown) to identify and/or locate the access port 30, e.g., to
identify the CEB 50 or elements 58. Optionally, as shown in FIG. 6,
the locator device 60' may include a pad 66,' e.g., an antiseptic
pad thereon.
[0073] Turning to FIGS. 10A-11C, another embodiment of a
self-sealing access port 130 is shown that may be provided separate
from a graft, blood vessel, or other tubular, curved, or
substantially flat structure (not shown). The access port 130 may
be attached to a body structure or otherwise implanted within a
patient's body, e.g., around or otherwise onto a tubular body
structure (e.g., a native or non-native, implanted tubular
structure), an organ, or other tissue structure within the
patient's body, as described further below. Generally, the access
port 130 includes a flexible cuff, patch, or other port body 132
and a side port 140 including an elastic ring or CEB 150, e.g.,
surrounding or embedded in a plug 142. As best seen in FIGS.
11A-11D, the port body 132 may have a first end 132a, a second end
132b, and a generally "C" shaped or other arcuate cross-section
between the first and second ends 132a, 132b, thereby defining side
edges 136 extending between the first and second ends 132a, 132b,
e.g., substantially parallel to a central longitudinal axis 134 of
the port body 132. Alternatively, the port body 132 may be
substantially flat or may have other shapes, e.g., corresponding to
the shape of a tissue structure to which the access port 130 may be
attached.
[0074] In an exemplary embodiment, the port body 132 may define a
periphery between the side edges 136 that is greater than one
hundred eighty degrees (180.degree.), e.g., between about
180-350.degree., thereby providing a "cuff" that may be positioned
around a tubular body structure, such as a tubular graft, fistula,
and the like, as described further below. For example, as shown in
FIG. 11D, the side edges 136 may be separated to open the cuff 132,
e.g., to a substantially flat or larger diameter shape that
facilitates positioning the port body 132 around a tubular
structure. Once in position, the side edges 136 may be released,
and the port body 132 may resiliently return towards its original
shape, e.g., to secure or stabilize the access port 130 around the
tubular structure. Alternatively, the port body 132 may define a
periphery less than one hundred eighty degrees (180.degree.) (not
shown), e.g., between about 10-180.degree., or may be substantially
flat, thereby providing a "patch" that may be attached to a wall of
a tubular structure, an organ, or other tissue structure, also as
described further below.
[0075] The port body 132 and side port 140 may be formed from
flexible and/or substantially nonporous base material, e.g.
silicone or other elastomeric material, and may be covered with
fabric or other porous material 160, as shown in FIGS. 11A-11D,
e.g., to promote tissue ingrowth after implantation and/or to
integrate the components of the access port 130. For example, the
access port 130 may be covered with a synthetic fabric 160, such as
polyester, PTFE, and the like, e.g., having a porosity or
internodal distance ("IND") between about forty and one hundred
fifty micrometers (40-150 .mu.m), e.g., between about sixty and one
hundred micrometers (60-100 .mu.m). In addition or alternatively,
the fabric 160 may have a loose weave on one surface (or
alternatively may have textured, fluffed, and/or selectively cut
fibers created through a variety of mechanical methods) that better
enables the base material to mechanically engage with the fibers of
the fabric during the forming, molding, layering, and/or assembly
process, e.g., to minimize and/or eliminate any gaps between the
base material and the fabric 160.
[0076] The ring 150 may be formed from an elastic, superelastic, or
shape memory material, such as a nickel-titanium alloy ("Nitinol"),
that may be resiliently expanded, e.g., to accommodate receiving a
needle, guidewire, catheter, introducer sheath, and the like
through the side port 140, and biased to compress radially inwardly
to self-seal the side port 140, similar to the CEB 50 described
above.
[0077] The side port 140 may be attached to or integrally formed
with the port body 132, e.g., such that the side port 140 extends
transversely from an outer surface of the port body 132. For
example, the side port 140 may extend substantially parallel to a
transverse axis 146 defining an acute angle relative to the
longitudinal axis 136, e.g., between about five and ninety degrees
(5-90.degree.), or about twenty degrees (20.degree.). Generally,
the side port 140 may include a flexible tubular or solid
cylindrical plug 142 including an elastic ring 150 surrounding
and/or embedded therein, e.g., to surround and/or compress the plug
142 radially inwardly on itself. Similar to the CEB 50 shown in
FIG. 2, the ring 150 may include a plurality of struts 152 defining
a serpentine pattern around a circumference of the ring 150, each
strut 152 including opposing ends that are alternately connected to
adjacent struts 152, e.g., by curved connectors or other elements
154, to define a zigzag or other serpentine pattern. Alternatively,
the ring 150 may include a mesh or other interconnected strut
pattern that may accommodate expansion of the ring 150 yet bias the
ring 150 to return inwardly to compress the plug 142 and/or seal
the side port 140.
[0078] For example, the plug 142 may be formed from silicone or
other elastomeric material, e.g., by one or more of molding,
casting, machining, spinning, and the like, having a desired
relaxed diameter or oval shape, e.g., between about 0.1-0.5 inch
(2.5-12.5 mm) or about 0.21-0.25 inch (5.25-6.25 mm). The ring 150
may be formed, for example, by laser cutting the struts 152 and
connectors or elements 154 from a section of Nitinol tubing, or by
cutting the struts 152 and elements 154 from a flat sheet and
rolling them into a tubular shape and attaching the opposing edges.
The ring 150 may be heat treated to provide a desired elasticity,
e.g., allowing the ring 150 to be elastically expanded yet biased
to a compress radially inwardly towards the original, relaxed
diameter. For example, the ring 150 may be biased to a diameter
smaller than the plug 142, and the ring 150 may be radially
expanded, positioned around the plug 142, and released, whereupon
the ring 150 compresses radially inwardly around the plug 142.
Alternatively, the ring 150 may be biased to a diameter similar to
the outer diameter of the plug 142, e.g., if the diameter of the
plug 142 is slightly larger or smaller than one or more instruments
likely to be inserted through the side port 140. Optionally,
another layer of silicone or other material may be applied around
the ring 150 and the assembly may be fused, e.g., by one or more of
heating, melting, fusing, casting, and the like, and/or the plug
142 may be softened to allow the ring 150 to become embedded within
the plug 142.
[0079] The port body 132 may be formed from a tubular, curved, or
substantially flat body of flexible base material, e.g., formed
from silicone or other elastomeric material, a substantially
nonporous material, a bioabsorbable material (as described
elsewhere herein), and the like, before or after forming the side
port 140. For example, the side port 140 may be mounted in a mold
or on a mandrel (not shown) such that a tubular body may be molded,
spun, cast, or otherwise formed on one end of the side port 140,
e.g., with the side port 140 defining the desired transverse angle
146. Once the tubular body is formed, it may be split or otherwise
separated along its length, e.g., generally opposite the side port
140 to provide the side edges 136 shown in FIGS. 11B and 11C.
Alternatively, the port body 132 may be molded, cast, or otherwise
formed in a "C" or other curved shape, e.g., if the port body 132
has a periphery substantially less than 360.degree., or in a
substantially flat shape, if desired.
[0080] It will be appreciated that the tubular, curved, or
substantially flat body for the port body 132 may be formed using
other methods, e.g., before or after the side port 140, and the
side port 140 may be attached to the outer surface of the port body
132, e.g., before or after splitting the tubular body. For example,
the side port 140 and port body 132 may be formed separately, e.g.,
and the side port 140 may be attached to the port body 132, e.g.,
by one or more of bonding with adhesive, sonic welding, fusing, and
the like. Generally, the port body 132 does not include an opening
over which the side port 140 is attached or otherwise formed,
although, if desired, an opening may be provided (not shown), e.g.,
to reduce the amount of material through which a needle or other
instrument must pass through the access port 130.
[0081] Once the port body 132 and side port 140 are formed and/or
attached together, exposed surfaces may be covered with fabric 160,
e.g., by one or more of stitching, bonding with adhesive, and the
like, to provide the completed access port 130. As shown in FIGS.
11A-11D, the inner and outer surfaces, end surfaces, and the like
of the port body 132, and the outer surfaces of the side port 140
are covered with one or more pieces of fabric 160, e.g., with
separate pieces of fabric being stitched, bonded with adhesive,
and/or otherwise attached together, as shown.
[0082] Optionally, the access port 130 (or other embodiments
herein) may include one or more features to facilitate identifying
and/or locating the side port 140, e.g., without direct
visualization since the access port 130 may be implanted
subcutaneously within a patient's body. For example, the side port
140 may extend from the port body 132 with sufficient height that
the side port 140 and the access port 130 may be implanted
sufficiently close to the patient's skin that the side port 140 may
be identified tactilely, e.g., by palpation. Alternatively, the
side port 140 may include one or more raised elements (not shown)
that facilitate tactilely locating the side port 140 through the
patient's skin. In addition or alternatively, the side port 140 may
include one or more ferromagnetic elements that may facilitate
locating the side port 140 using a magnetic locator, as described
elsewhere herein, echogenic elements that may facilitate locating
the side port 140 using an external ultrasound device, and the
like.
[0083] The resulting access port 130 may be attached to a tubular
structure, e.g., a tubular graft, fistula, blood vessel, and the
like, or other tissue or body structure (not shown), e.g., before
or after the tubular structure is implanted within a patient's
body. For example, if the tubular structure is a graft to be
implanted in a patient's body, the access port 130 may be attached
to the tubular structure before introduction into the patient's
body, e.g., as described below with reference to FIGS. 12A and
12B.
[0084] In a further alternative, if the tubular structure has
already been implanted, created, or accessed within the patient's
body, the target site may be accessed, e.g., using known
procedures, and the access port 130 may be secured around or to the
tubular, tissue, or body structure in situ. For example, if the
port body 132 has a curved shape greater than 180.degree., the side
edges 136 of the port body 132 may be opened and the access port
130 positioned at a desired location on the tubular structure. The
side edges 136 may then be released such that the port body 132
wraps at least partially around the tubular structure, e.g.,
depending upon whether the periphery of the port body 132 is
similar to or smaller than the circumference of the tubular
structure. If the port body 132 has a curved shape less than
180.degree. or is substantially flat, the port body 132 may simply
be placed against the structure at a desired location.
[0085] Optionally, the port body 132 may be secured to the outer
surface of the tubular structure, e.g., by one or more of stitching
with sutures, bonding with adhesive, and the like. For example, in
one embodiment, the inner surface of the port body 132 may include
an adhesive or other material (not shown), which may bond to the
tubular structure or another adhesive component applied to the wall
of the tubular structure, for facilitating attaching or otherwise
securing the port body 132 to the tubular structure. In addition or
alternatively, micro-barbs or other features (not shown) may be
provided on the inner surface of the port body 132, e.g., to anchor
and/or otherwise enhance engagement between the port body 132 and
the tubular structure.
[0086] In addition, if desired, the port body 132 may include one
or more features on the first and/or second ends 132a, 132b to
reduce risk of the tubular structure kinking. For example, spiral
wire, axial tabs, or other features (not shown) may extend axially
or circumferentially from the first and/or second ends 132a, 132b
at least partially around the periphery of the port body 132. Such
features may be formed from metal, such as stainless steel or
Nitinol, polymers, composite materials, and the like. For example,
spiral strands may extend beyond the port body 132 that may be
wrapped at least partially around the tubular structure to reduce
the risk of kinking immediately adjacent the access port 130.
[0087] If the port body 132 has a periphery less than one hundred
eighty degrees (180.degree.), is substantially flat, and/or is
sufficiently flexible, the access port 132 may be attached to any
desired structure sized to receive the port body 132 thereon. The
port body 132 may have sufficient flexibility to conform
substantially to the shape of the structure to which it is
attached. For example, the access port 130 may be attached to the
wall of a tubular structure, or to an organ, e.g., to the apex of a
heart, or other tissue or body structure, to which repeated access
may be desired, e.g., by one or more of suturing, bonding with
adhesive, and the like. Although the access port 130 may be located
subcutaneously, the side port 140 may facilitate percutaneous
access into the body structure to which the access port 130 is
attached.
[0088] For example, after implantation and sufficient healing, a
needle (not shown) may be inserted through the side port 140, e.g.,
through the ring 150 to create a passage through the plug 142, and
then one or more instruments may be advanced over or through the
needle, e.g., a guidewire, catheter, introducer sheath, and the
like. The ring 150 may resiliently expand to accommodate the
instrument(s) being inserted through the side port 140 into the
body structure. After completing one or more diagnostic or
therapeutic procedures at one or more sites accessed via the side
port 140, any instruments may be removed, and the ring 150 may
resiliently compress inwardly, thereby substantially closing and/or
sealing the side port 140 automatically, thereby reducing or
eliminating the need to provide manual compression or other
measures to reduce bleeding from the access site.
[0089] Turning to FIGS. 12A and 12B, another embodiment of an
access port 230 is shown that is integrally formed on a tubular
structure, such as a tubular graft 210, e.g., formed from ePTFE or
other material. Generally, the access port 230 includes a port body
232, a side port 240, and a ring 250, similar to the previous
embodiments. The side port 240 and ring 250 may be formed similar
to methods described above, e.g., such that the ring 250 surrounds
or is embedded in base material of the side port 240, and/or
compresses the base material radially inwardly. The port body 232
may be integrally formed with the side port 240 and/or formed
separately and attached thereto, and then the port body 232 may be
split, e.g., as described above. The side edges (not shown) of the
port body 232 may be separated and the access port 230 positioned
around the tubular graft 210. Alternatively, the port body 232 may
not be split, and the access port 230 may simply be directed over
one end of the graft 210 to a desired location in an enclosed
tubular configuration.
[0090] The access port 230 may then be attached to the graft 210,
e.g., by one or more of bonding with adhesive, fusing, stitching
with sutures, micro-barbs or other features on the inner surface,
and the like. Fabric (not shown) may be stitched or otherwise
attached over exposed surfaces of the access port 230 and/or graft
210 to provide a tubular graft 210 including a self-sealing access
port 230 that may implanted with a patient's body together.
[0091] Turning to FIGS. 13A-14C, another embodiment of a
self-sealing access port 330 is shown in the form of a cuff
including a port body 332 of flexible base material defining a
central longitudinal axis 336, a plurality of bands 350 surrounding
or embedded within the port body 332, and fabric 360 covering
exposed surfaces. The port body 332 has a generally "C" shaped
cross-section including longitudinal edges 336 extending between
first and second ends 332a, 332b. Alternatively, the port body 332
may be provided as a patch or other body, e.g., including a
substantially planar or curved surface that may be attached to a
tissue structure or other body structure, as described elsewhere
herein. The port body 332 may be formed from one or more layers of
flexible base material, e.g., silicone or other elastomeric or
nonporous and/or flexible material, similar to the previous
embodiments. In addition or alternatively, the port body 332 may be
formed from bioabsorbable material, e.g., polyethylene glycol, PLA,
PGA, small intestinal submucosa (SIS), and the like, as described
further elsewhere herein.
[0092] The bands 350 may be formed from continuous rings or "C"
shaped collars of Nitinol or other elastic, superelastic, or shape
memory material formed, e.g., laser cut, mechanically cut, stamped,
machined, and the like, from a tube, wire, or sheet, similar to the
CEB 50 and other embodiments herein. Each band 350 may extend at
least partially around the periphery of the port body 332
transverse to the longitudinal axis 336. For example, each band 350
may include a plurality of longitudinal struts 352 defining a
serpentine pattern around a periphery of the port body 332, each
strut 352 including opposing ends that are alternately connected to
adjacent struts 352 by curved circumferential connectors, struts,
or elements 354, e.g., to define a zigzag or other serpentine
pattern. The longitudinal struts 352 may extend substantially
parallel to the longitudinal axis 334 or, alternatively, may extend
diagonally or helically relative to the longitudinal axis 334 (not
shown).
[0093] Alternatively, the access port 330 may include a contiguous
mesh or other enclosed or open pattern including struts at least
partially surrounding openings (not shown) through which one or
more instruments may be inserted, as described further elsewhere
herein. For example, individual bands or a substantially continuous
mesh sheet may be provided that include interconnected struts
defining generally diamond-shaped or other enclosed openings
therebetween (not shown), with the struts being separable to
increase the size of the openings, e.g., to accommodate receiving
one or more instruments therethrough, as described elsewhere
herein. Exemplary mesh patterns that may be used are shown in U.S.
Pat. Nos. 4,733,665, 5,344,426, and 5,591,197 the entire
disclosures of which are expressly incorporated by reference
herein. In further alternatives, the access port 330 may include
one or more wires or other elongate filaments wound helically or
otherwise around the port body 332 and/or along a desired length of
the port body 332, e.g., a single helical element, multiple helical
filaments braided or otherwise wound together into a mesh, and the
like.
[0094] In a further alternative, struts or bands may extend axially
along a length of the access port 330 (not shown). For example, a
plurality of substantially straight wires or other filaments may be
embedded within or otherwise fixed to the base material. The
filaments may be spaced apart sufficiently to accommodate inserting
one or more instruments (not shown) through the access port 330,
with the filaments moving laterally to accommodate the
instrument(s) passing therethrough and resiliently returning to
their original configuration to substantially seal the access port
330, similar to other embodiments herein. Alternatively, the
filaments may include a zigzag or other pattern that extends
transversely while the filaments extend generally axially between
the ends of the access port 330. Further, the filaments or struts
may impose a substantially continuous compressive force on the
adjacent base material, which may enhance sealing any passages
created through the base material, similar to other embodiments
herein.
[0095] The struts, filaments, or features of the bands or mesh,
e.g., the struts 352 and curved connectors 354 shown in FIGS. 13A
and 13B, may have any desired cross-section. For example, the
features may have generally round, elliptical, rectangular, or
square cross-sections, optionally, having tapered or rounded
surfaces to facilitate passing an instrument between the features.
For example, the features may be formed with a rectangular
cross-section that may have rounded or tapered edges, e.g., by one
or more of electro-polishing, machining, laser cutting, and the
like. Optionally, the features may have a thickness (extending
radially relative to the central longitudinal axis 336) that is
greater than their width (extending axially and/or
circumferentially), which may provide increased radial support yet
accommodate separation of the features "laterally," as described
further elsewhere herein.
[0096] In the embodiment shown in FIGS. 13A and 13B, each band 350
has a generally cylindrical shape, e.g., including first and second
longitudinal ends that are spaced apart axially from one another
and aligned around the periphery of the port body 332, e.g.,
substantially perpendicular to the longitudinal axis 334.
Alternatively, the bands 350 may extend helically around the
periphery of the port body 332 (not shown) and/or may have other
shapes or configurations including an axial length dimension along
a length of the port body 332 and a peripheral dimension extending
at least partially around the periphery of the port body 332.
[0097] The bands 350 may be disposed immediately adjacent one
another, e.g., with adjacent bands 350 in phase with one another.
For example, as shown in FIGS. 13A and 13B, the curved connectors
354 on the first end of a first band 350 may be disposed between
the curved connectors 354 on the second end of an adjacent band
350. Alternatively, adjacent bands 350 may be spaced axially apart
from one another (not shown), thereby providing an unreinforced
annulus of the port body 332 between adjacent bands 350, which may
accommodate introducing relatively large instruments between the
struts 352 and/or bands 350, as described further below. In another
alternative, portions of adjacent bands may overlap one another
(not shown) or a braided or other multiple layer mesh may be
provided (also not shown), as long as struts or other elements of
the mesh are free to move laterally and/or resiliently to
accommodate one or more instruments through openings between the
elements.
[0098] In a further alternative, adjacent bands 350 may be out of
phase with one another, e.g., such that the curved connectors 354
of adjacent bands 350 are disposed adjacent one another, e.g.,
aligned axially or diagonally relative to one another (not shown).
In this alternative, adjacent bands may define openings surrounded
by pairs of struts from each adjacent band, which may accommodate
receiving relatively large instruments through the openings yet
substantially closing the openings once the instrument(s) are
removed. Optionally, one or more of the curved connectors 354 on a
band 350 may be coupled to one or more curved connectors 354 of an
adjacent band 350. For example, adjacent curved connectors 354 may
be coupled directly together, or may be coupled by a flexible link
(not shown), e.g., to limit movement of adjacent bands 350 relative
to one another.
[0099] Turning to FIG. 13A, the access port 330 may be formed by
initially creating a tubular body of silicone, PET, or other
flexible, nonporous, and/or bioabsorbable base material having a
desired length and/or diameter for the port body 352, e.g., by one
or more of molding, casting, machining, spinning, and the like. For
example, the tubular body may have a length between about one and
ten centimeters (1-10 cm), a diameter between about one and forty
millimeters (1-40 mm), and a wall thickness between about 0.5 and
five millimeters (0.5-5.0 mm).
[0100] The set of bands 350 may be formed individually or
simultaneously, e.g., by laser cutting from a tube, winding one or
more strands in a zigzag or other circuitous pattern around a
mandrel, and the like. For example, a length of Nitinol wire or
other material may be wound around a cylindrical mandrel (not
shown) between posts to define a zigzag or other circuitous pattern
to define an enclosed band (or entire set of bands) or may be wound
helically along a mandrel to define a substantially continuous
helical band. Alternatively, a single tube may be cut to create the
set of bands 350 or a substantially continuous mesh of struts (not
shown), as desired. The individual or set of bands 350 may have
lengths between about three and one hundred twenty five millimeters
(3.0-125 mm), e.g., coextensive with or less than the length of the
port body 352.
[0101] Alternatively, the bands 350 may be formed from a flat
sheet, e.g., by one or more of laser cutting, mechanically cutting,
etching, stamping, and the like, one or more sets of struts and
connectors from the sheet, and then rolling the sheet. The
longitudinal edges of the rolled sheet may remain separate, e.g.,
to provide "C" shaped bands, or alternatively the longitudinal
edges may be attached together, e.g., by one or more of welding,
soldering, fusing, bonding with adhesive, and the like, to provide
an enclosed band. In a further alternative, a set of bands 350,
e.g., providing an entire set for the access port 330, may be
formed simultaneously from a tube or sheet, particularly if the
bands 350 are connected together, e.g., by links or directly by
adjacent connectors 354.
[0102] The bands 350 may be heat treated and/or otherwise processed
to provide a desired finish and/or mechanical properties to the
bands 350. For example, the bands 350 may be heat treated such that
the bands 350 are biased to a desired relaxed diameter, e.g.,
substantially the same as or smaller than the tubular body for the
port body 332, yet may be resiliently expanded and/or have one or
more struts 352 and/or curved connectors 354 resiliently deformed
to accommodate receiving a needle or other instrument (not shown)
between adjacent struts 352, connectors 354, and/or bands 350, as
described further below. Alternatively, if the bands 350 are formed
from a sheet of material, the sheet may be heat treated and/or
otherwise processed to provide the desired shape and/or properties
for the bands 350 formed from the sheet.
[0103] In an exemplary embodiment, for Nitinol material, the bands
350 may be heat treated such that the A.sub.f temperature for the
material is less than body temperature (about 37.degree. C.), e.g.,
between about ten and thirty degrees Celsius (10-30.degree. C.).
For example, the Nitinol material may remain substantially in an
Austenitic state when the access port 330 is implanted within a
patient's body, yet may operate within a superelastic range, e.g.,
transforming to a stress-induced martensitic state when an
instrument is inserted through the openings in the access port 330,
as described elsewhere herein. Alternatively, the Nitinol material
may be heat treated to take advantage of the temperature-activated
or other shape memory properties of the material. For example, the
material may be heat treated such that the bands 350 are
substantially martensitic at or below ambient temperature, e.g.,
below twenty degrees Celsius (20.degree. C.), such that the bands
350 may be relatively soft and/or plastically deformable, which may
facilitate manipulation, introduction, or implantation of the
access port 330. At around body temperature, e.g., at thirty seven
degrees Celsius (37.degree. C.) or higher, the bands 350 may be
substantially austenitic, e.g., to recover any desired shape
programmed into the material and to provide elastic or superelastic
properties to the bands 350 once the access port 330 is implanted
within a patient's body.
[0104] With continued reference to FIG. 13A, to form the access
port 330, a set of bands 350 may be fixed to, e.g., placed on,
bonded to, or embedded in, the tubular body or other base material
of the port body 332. For example, in their relaxed state, the
bands 350 may have a diameter smaller than the base material of the
port body 332, and the bands 350 may be expanded radially
outwardly, positioned around the tubular body, and released such
that the bands 350 apply a radially inward compressive force
against the tubular body. Such compression may be sufficient to
bias the port body 332 to a desired diameter, e.g., smaller than a
tubular body to which the access port 330 may be secured, for
example, to reduce migration and/or otherwise secure the access
port 330. In addition, such compression may impose a substantially
continuous compressive force on the port body 332, which may
enhance the self-sealing function of the access port 330.
Alternatively, the bands 350 may be biased to a diameter similar to
the outer surface of the tubular body such that the bands 350
surround the tubular body without substantial radially inward
compression. In this alternative, the bands 350 may remain in a
substantially relaxed state and/or may not apply a radially inward
compressive force against the base material of the port body
332
[0105] Optionally, the bands 350 may be expanded "laterally" in
addition to or instead of being radially expanded. For example, the
bands 350 may be expanded from a relaxed state to increase the
spacing of the struts or filaments, i.e., increase the size of the
openings defined by the bands 350, and then placed on, embedded in,
and/or otherwise attached to the base material of the port body
332. In this embodiment, once the bands 350 are fixed to the port
body 332, the bands 350 may be released such that the bands 350 are
biased to return laterally inwardly towards the relaxed state,
thereby biasing the struts and openings to a smaller size, yet
accommodating the struts moving laterally to accommodate an
instrument being inserted through the openings, as described
elsewhere herein.
[0106] As described above, once fixed to the port body 332, the
bands 350 may be spaced apart from, may contact, may overlap, or
may be nested between adjacent bands 350, e.g., in phase or out of
phase with one another, as desired. Alternatively, if the bands 350
are connected to one another, the entire set of bands 350 may be
positioned around the tubular body with or without expanding and
releasing the bands.
[0107] Optionally, with the bands 350 surrounding, placed against,
or fixed relative to the base material of the port body 332,
another layer of silicone, PET, or other flexible base material may
be applied around the bands 350 to further form the port body 332,
thereby embedding the bands 350 within the base material. For
example, an outer layer of silicone may be applied around the bands
350 and the assembly may be heated, cured, or otherwise processed
to fuse, melt, or otherwise bond the material of the outer layer to
the bands 350 and/or the material of the tubular body.
Alternatively, the tubular body may be softened or otherwise
treated to allow the bands 350 to become embedded therein, or the
tubular body may be formed around the bands 350, if desired. In a
further alternative, the bands 350 may be secured around the
tubular body, e.g., by one or more of bonding with adhesive, sonic
welding, fusing, and the like.
[0108] As shown in FIGS. 13A and 13B, a plurality of bands 350 are
embedded in or secured around the port body 332, e.g., two, three,
four, five (as shown), or more bands 350, as desired. For example,
as shown, the bands 350 may be provided along substantially the
entire length of the port body 332. Alternatively, the bands 350
may be provided only in a central region of the port body 332,
e.g., with regions adjacent the first and second ends 332a, 332b
including unsupported silicone or other base material (not shown).
In this alternative, the bands 350 may provide a self-sealing or
self-closing access region only along the central region with the
unsupported end regions providing a transition, e.g., to reduce
kinking and the like when the access port 330 is attached to a
tubular structure. The unsupported end regions may have
substantially uniform properties similar to the central region or
may have different properties. For example, the end regions may
have a tapered thickness, e.g., relatively thick immediately
adjacent the central region and tapering towards the ends of the
port body 332, may be formed from a relatively softer durometer
material, and the like.
[0109] In a further alternative, the access port may include
multiple regions embedded with or otherwise supported by bands that
are separated by unsupported regions of the port body (not shown).
Thus, in this alternative, a self-sealing cuff or patch may be
provided that includes multiple spaced-apart self-closing access
regions separated by unsupported regions.
[0110] Returning to FIGS. 13A and 13B, once the bands 350 are
embedded within or otherwise secured to the port body 332, the port
body 332 may be split or otherwise separated, e.g., by one or more
of laser cutting, mechanical cutting, and the like, through the
silicone material and the bands 350, to provide the side edges 336,
as shown in FIG. 13B. Alternatively, the bands 350 may be formed as
discontinuous "C" shaped collars that may be attached around or
embedded within the port body 332 before or after splitting the
port body 332 to create the longitudinal edges 336. In a further
alternative, a length of base material with embedded bands
corresponding to multiple individual access ports may be formed
using the methods described above, and the resulting assembly may
be cut or otherwise separated into individual port bodies 332, if
desired. In yet a further alternative, the bands and port bodies
may not be cut longitudinally, if a tubular access port is desired,
similar to other embodiments herein.
[0111] Turning to FIGS. 14A-14C, fabric 360 may be applied over any
exposed surfaces, e.g., over the outer, inner, and end surfaces of
the port body 332 to provide the completed access port 330. For
example, one or more pieces of fabric 160 may be wrapped around the
port body 332 and stitched together and/or to the port body 332,
e.g., similar to other embodiments herein. Optionally, the access
port 330 may include one or more tactile elements, ferromagnetic
elements, echogenic elements, and the like (not shown), e.g., to
facilitate locating the access port 330 and/or bands 350 when the
access port 330 is implanted subcutaneously or otherwise within a
patient's body.
[0112] During use, the access port 330 may be positioned around a
tubular structure, e.g., a graft before or after implantation, a
blood vessel, fistula, or other tubular structure (not shown)
exposed or otherwise accessed within a patient's body. For example,
the side edges 336 may be separated, and the port body 332
positioned around or otherwise adjacent a tubular structure. The
side edges 336 may be released to allow the port body 332 to
resiliently wrap at least partially around the tubular structure
and/or the port body 332 may be attached to the tubular structure,
e.g., by one or more of bonding with adhesive, suturing, fusing,
and the like. Alternatively, if the access port includes an
enclosed tubular port body (not shown), the access port may be
directed over a tubular structure from one end thereof (which may
be preexisting or may be created by cutting the tubular
structure).
[0113] In an alternative embodiment, an access port similar to
access port 330 may be attached to a tubular graft or other
structure before introduction and/or implantation within a
patient's body. In another alternative, the access port 330 may be
integrally formed into the wall of a graft, e.g., during
manufacturing of the graft, if desired. For example, rather than
providing a separate port body 332, the bands 350 or other support
elements may be integrally molded or otherwise embedded within a
wall of a tubular graft or other implant. Thus, the implant may
include an integral access port that operates similar to the other
embodiments herein.
[0114] In an alternative embodiment, shown in FIG. 20A, an access
port 330' may be provided that includes a plurality of separate
port bodies 332' that may be placed around a vessel or other
tubular structure 90. For example, as shown, the access port 330'
includes a pair of port bodies 332' including bands or other
support elements (not shown) that surround the vessel 90, e.g., in
a clamshell type configuration. The port bodies 332' may be
attached to the vessel 90 separately or may include one or more
cooperating connectors, e.g., hinged elements, sutures, and the
like (not shown), that attach the adjacent edges of the port bodies
332' together. In a further alternative, shown in FIG. 20B, an
access port 330'' is shown that includes a port body 332'' having a
hinged region 333.'' Thus, the port body 332'' may be opened along
its length, placed around the vessel 90, and then closed such that
the side edges 336'' are disposed adjacent one another. The side
edges 336'' may be spaced apart from one another, contact one
another, or overlap one another, if desired, and/or may include one
or more connectors (not shown) for securing the side edges 336''
relative to one another, if desired.
[0115] In either of these embodiments, the access port 332,' 332''
may have a diameter similar to the outer diameter of the vessel 90
or may have a slightly smaller diameter if it is desired to apply a
radially compressive force to the vessel 90. The access ports 332,'
332'' may be attached to the vessel 90, e.g., by one or more of
stitching with sutures, bonding with adhesive, and the like,
similar to other embodiments herein. Optionally, micro-barbs or
other features (not shown) may be provided on the inner surfaces of
the port bodies 332' similar to other embodiments herein.
[0116] Alternatively, the port bodies 332,' 332'' may be provided
as rectangular, substantially flat or otherwise sufficiently
flexible sheets that may simply be wrapped around a vessel 90 and
secured thereto, e.g., by bonding, suturing, or clipping the port
bodies 332,' 332'' to the vessel 90 and/or to secure the ends of
the port bodies 332,' 332'' to one another. The resulting access
ports 332,' 332'' may substantially surround the entire
circumference of the vessel 90 and/or partially overlap, which may
reduce the risk of leakage from the vessel 90, e.g., due to
over-penetration, e.g., if a needle is directed into one side and
accidentally out the other side of a vessel, as described elsewhere
herein.
[0117] Returning to FIGS. 14A-14C and with reference to the access
port 330 (although the description may apply equally to other
embodiments herein), if it is desired to access a lumen of the
tubular structure, a needle (not shown) may be introduced through
the patient's skin over the access port 330, and directed through
the port body 332 into the lumen. The thickness of the access port
330 may facilitate identifying the ends of the access port 330,
e.g., by palpation, since the ends may be identified tactilely
relative to the adjacent regions of the tubular structure. Thus,
the access port 330 may reduce the risk of accidental sticks in
regions of the tubular structure not covered by the access port
330. Optionally, similar to other embodiments herein, the access
port 330 may include one or more locator elements (not shown),
which may be identified by an external probe, e.g., a magnetic or
ultrasound device, to facilitate identifying the location of the
access port 330.
[0118] As the needle is inserted, if the needle encounters any of
the struts 352, connectors 354, or other features of the bands 350,
the encountered features may resiliently move away from the needle
to create a passage through the access port 330 into the lumen. If
one or more larger instruments are subsequently introduced through
the access port 330, e.g., over a guidewire advanced through the
needle or over the needle itself, the struts 352, connectors 354,
and/or other features of the bands 350 may resiliently separate to
create a sufficiently large passage through the port body 332 to
accommodate the instrument(s). Generally, the struts 352,
connectors 354, and/or other features of the bands 350 separate
"laterally," i.e., circumferentially and/or axially within the
cylindrical surface defined by the port body 332, to provide a
passage through the port body 332. As used herein, "laterally"
refers to movement of the features of the bands 350 or other mesh
substantially in a direction around the circumference and/or along
the length of the port body 332 within the base material and
generally not out towards the inner or outer surfaces of the port
body 332 (i.e., "within the plane" of the port body 332). For
example, if the port body 332 were substantially flat within a
plane, laterally would refer to movement of the features of the
bands substantially within the plane and generally not out of the
plane towards the inner or outer surfaces.
[0119] Optionally, the material of the port body 332 may include
one or more surface features to facilitate penetration of a needle
or other instrument through the access port 330. For example, the
port body 332 may have a variable thickness, e.g., defining valleys
and ridges along its outer surface (not shown), with the ridges
overlying struts or other features of the bands 350 and the valleys
disposed between the features of the bands 350. When a needle or
other instrument (not shown) is inserted through the access port
330, the ridges may guide the tip of the needle into the regions
between the struts of the bands 350, e.g., to reduce the risk of
interference between the needle and the bands 350.
[0120] After a procedure is completed via the access port 330 and
the lumen of the tubular structure, any instruments may be removed,
whereupon the bands 350 may resiliently return towards their
original shape, e.g., laterally inwardly towards their original
configuration, thereby compressing the material of the port body
332 to close any passage created therethrough. Thus, the bands 350
may provide a self-sealing or self-closing feature that
automatically substantially seals any passages created through the
port body 332 by a needle or other instruments.
[0121] For example, if the spacing of the struts or other features
of the bands 350 is smaller than the cross-section of the
instrument(s) inserted through the access port 330, the features
may separate to create a passage through the access port 330 that
is larger than the spacing of the features in their relaxed state.
However, even if the spacing of the features is larger than the
cross-section of the instrument(s) inserted through the access port
330, the bands 350 may provide sufficient bias within the plane of
the port body 332 to bias the port body material to resiliently
close laterally inwardly around any passage created therethrough to
automatically close the passage. Thus, the elasticity/bias of the
bands 350 may reinforce and/or bias the material of the port body
332 to allow repeated access through the access port 330, while
automatically closing any passages to self-seal the access port
330. The bias or support of the port body material between the
struts of the bands 350 may also reduce the risk of the material
breaking down over time due to multiple penetrations.
[0122] One of the advantages of the access port 330 is that a
needle or other instrument may be introduced at multiple locations
through the port body 332, unlike the access ports 130, 230. As
long as the needle is inserted through a region of the access port
330 including and/or supported by one or more bands 350, the
features of the bands 350 may separate or otherwise open to
accommodate the needle and resiliently return towards their
substantially stress free or preloaded original configurations when
all instruments are removed. Thus, in this embodiment, there may be
no need for locator elements (unless provided to facilitate
identifying the ends of the access region), or a single access
region may provide multiple access sites, rather than having to
implant multiple discrete access ports.
[0123] In addition, such bands 350 may protect the accessed tubular
structure from over-penetration of needles or other instruments.
For example, if the access port 330 substantially surrounds the
tubular structure, a needle or other instrument that is
inadvertently inserted into one side of the access port 330 through
the entire tubular structure and out the opposite side of the
access port 330 may be removed without substantial risk of bleeding
or other leakage from the posterior location as well as the
anterior location since the access port 330 may self-seal both
openings.
[0124] Optionally, if the port body 332 has a periphery defining
less than one hundred eighty degrees (180.degree.) or is
substantially flat, the access port 330 may be applied as a patch
to the surface of any body structure, e.g., a tubular structure,
such as a graft, fistula, blood vessel, and the like, or to an
organ, abdominal wall, or other tissue structure. The "patch" may
have a variety of shapes and/or sizes depending upon the
application and/or may have sufficient flexibility to conform to
the shape of anatomy to which the patch is applied. For example,
the port body 332 may have a two-dimensional shape, e.g., a
rectangular, square, oval, or circular shape, with bands 350
provided along the entire surface area of the port body 332 or
spaced apart inwardly from an outer perimeter of the "patch." Such
patches may be created by cutting or otherwise separating a desired
shape from the tubular body described above after embedding or
securing bands thereto. Alternatively, individual patches may be
created by embedding or securing flat bands to patches of silicone
or other base material formed into the desired shape.
[0125] In a further alternative, the patch may be created by
laminating multiple layers of material to create a self-sealing
structure that may be attached to a tissue structure. For example,
each layer may include elastic support elements, e.g., a mesh,
struts, and the like, that support one or more layers of base
material within a plane of the base material(s). Alternatively, one
or more layers of base material may be provided that has sufficient
flexibility and bias such that the support elements may be
omitted.
[0126] The resulting patch may accommodate creating an opening
through the base material(s) of the layers when one or more
instruments are inserted through the patch, i.e., with the support
elements moving laterally within the plane of the base material(s).
After removing the instrument(s), the support elements may bias the
base material(s) of the respective layers laterally towards their
original configuration, thereby automatically closing the
opening.
[0127] Alternatively, the access port 330 may be provided in a
three-dimension configuration, e.g., a conical, parabolic, or other
shape (not shown). In addition or alternatively, the access port
330 may be provided in a curved cylindrical (e.g., substantially
uniform or tapered) or other shape having a desired arc length,
e.g., up to sixty degrees (60.degree.), one hundred twenty degrees
(120.degree.), or between five and three hundred sixty degrees
(5-360.degree.), or between one hundred eighty and three hundred
sixty degrees (180-360.degree.), and the like. The port body 332
may be biased to a predetermined three-dimensional shape yet
sufficiently flexible to accommodate the actual anatomy
encountered, e.g., having one or more bands or other structures
including elastic struts embedded within or otherwise secured to a
flexible base material, such as silicone or other elastomer,
similar to other embodiments herein.
[0128] Optionally, the access port 330 may be used as a patch or
surgical mesh, e.g., which may be attached or otherwise secured to
weakened areas of tissue or organs to provide reinforcement in
addition to allowing subsequent access, if desired. For example,
the access port 330 may be applied as a patch for vascular repair,
e.g., over a pseudo-aneurysm, or after excising a pseudo-aneurysm
to reinforce the region and/or allow subsequent access.
[0129] Turning to FIG. 18, an exemplary embodiment of a surgical
patch 530 is shown that includes one or more layers of base
material 532, e.g., defining a substantially flat or curved
"plane," and a plurality of support elements or bands 550 embedded
or otherwise attached to the base material 530. For example, the
base material 532 may include one or more layers of silicone or
other elastomeric material that may be biased to a flat or curved
planar shape or may be "floppy," i.e., may have no particular shape
and may conform substantially to any desired shape. As shown, the
support elements include a plurality of bands 550 including
features, e.g., struts 552 alternately connected by curved
connectors 554, similar to other embodiments herein. The bands 550
may extend along a substantially linear axis across the base
material 532, e.g., defining a sinusoidal or other alternating
pattern, adjacent to and substantially parallel to one another.
Thus, the features, e.g., struts 552 and connectors 554, may
support the base material 532, such that the support elements 550
may be separable laterally to accommodate receiving one or more
instruments (not shown) through the base material 532, yet
resiliently biased to close any openings through the base material
532 created by the instrument(s), similar to other embodiments
herein.
[0130] Alternatively, the patch 530 may include one or more layers
of base material 532 without the support elements 550 covered with
fabric or other material (not shown). The base material 532 may be
constructed to be self-supporting and resiliently biased to allow
the creation of passages therethrough by a needle or other
instrument (not shown), yet self-close the passage(s) upon removal
of the instrument(s) to prevent substantial leakage through the
patch 530. For example, each layer of base material may provide
axial strength in a desired axial direction, and multiple layers
may be attached together with the axial directions orthogonal or
otherwise intersecting one another. The direction of axial strength
may be achieved by selection of the polymer or other material for
the base material or by embedding strands, wires, or other axial
elements within the base material (not shown). Similar to other
embodiments herein the patch 530 may be biased to a substantially
flat configuration, a curved configuration, or may be "floppy," as
described elsewhere herein.
[0131] In addition, as shown in FIG. 18, the surgical patch 530 may
include a sewing ring or cuff 560 extending around a periphery of
the base material 532, e.g., to facilitate securing the patch 530
to tissue, as described further below. For example, the sewing ring
560 may include one or more layers of fabric or other material,
e.g., optionally filled with foam, fabric, or other resilient,
flexible, and/or penetrable material, attached to the periphery of
the base material 532, e.g., by stitching with sutures, bonding
with adhesive, and the like. The base material 532 may also be
covered with fabric or other material, e.g. the same or different
material than the sewing ring 560, to enhance tissue ingrowth
and/or integrate the components of the patch 530.
[0132] The patch 530 may have a generally round shape, e.g., an
elliptical, oval, or substantially circular shape. Alternatively,
the patch 530 may have a square or other rectangular shape, or
other geometric shape, as desired.
[0133] In an alternative embodiment, the patch 530 may be provided
in a "cut-to-length" configuration, e.g., an elongate sheet or roll
(not shown) of base material 532, having a predetermined width and
a length sufficient to provide multiple individual patches. In this
alternative, the sewing ring 560 may be omitted or may be provided
along the longitudinal edges of the sheet or roll. Optionally, the
sheet or roll may include weakened regions to facilitate separating
individual patches or may include unsupported regions without
support elements 550 between regions with support elements 550,
e.g., that may be easily cut otherwise separated to allow
individual patches to be separated from the sheet or roll.
[0134] Turning to FIGS. 19A-19C, an exemplary method is shown for
vascular repair using the patch 530 of FIG. 18. As shown in FIG.
19A, a blood vessel 90 may include a weakened region 92 in need of
repair. Turning to FIG. 19B, the weakened region 92 and adjacent
tissue may be resected to create an opening 94, e.g., corresponding
to the size and shape of the patch 530. The patch 530 may then be
attached within or over the opening 94, e.g., by suturing the
sewing ring 560 to the vessel wall surrounding the opening 94.
Alternatively, the patch 530 may be attached to the wall of the
vessel 90 without removing the weakened region 92, e.g., by
attaching the patch 530 to the vessel 90 over the weakened region
92 or within the lumen underlying the weakened region 92, thereby
supporting the weakened region 92. In another alternative, the
patch 530 may be attached to a vessel wall that does not include a
weakened region, e.g., as a prophylactic measure to prevent a
weakened region from developing at the site of implantation. The
patch 530 may thereafter provide a structure for supporting the
vessel wall and/or provide a self-closing structure allowing
multiple access to the vessel 90, similar to other embodiments
herein.
[0135] In another embodiment, an access port patch may be attached
to the apex of the left ventricle of a heart to facilitate
trans-apical procedures, e.g., aortic valve replacement, and the
like. Such a patch may allow one-time or repeated access through
the LV apex into the left ventricle. Once the procedure is
completed, any instruments introduced through the patch may be
removed, and the patch may provide substantially instantaneous
sealing of the LV apex.
[0136] In another option, the access port 330 may be provided in a
tubular or "C" shaped configuration, and may be introduced into a
blood vessel or other body lumen. For example, the access port 330
may be rolled or otherwise compressed, and loaded into a catheter,
delivery sheath, and the like (not shown). Alternatively, the
access port 330 may be advanced over a needle, e.g., a dialysis
needle, into the interior of a graft, fistula, or other tubular
structure after dialysis. Once deployed within a lumen of a tubular
structure or body lumen, the access port 330 may be attached to the
wall of the body lumen, e.g., by one or more of stitching with
sutures, bonding with adhesive, interference fit due to the radial
bias of the access port 330, and the like. Thus, the access port
330 may provide an immediate barrier to leakage through a wall of
the body lumen, e.g., to substantially seal a puncture site from
the interior of the body lumen. In addition, the access port 330
may allow the lumen to be subsequently accessed again, as desired,
with the access port 330 providing a self-sealing access region,
similar to other embodiments herein.
[0137] Optionally, the access port 330 may be biased to expand to a
diameter larger than the body lumen within which it is implanted.
For example, in dialysis patients in which an AV fistula is
created, it may be desirable to remodel, e.g., expand, the native
vein attached to an artery to create the fistula. If the access
port 330 is biased to a diameter larger than the existing vein,
e.g., similar to the diameter of the artery, the access port 330
may apply a radially outward and/or circumferential force against
the surrounding wall of the vein. This bias may accelerate or
enhance the natural remodeling of the vein that may occur, e.g.,
when the vein is exposed to arterial blood pressure. The entire
access port 330 may include bands 350 to provide a self-closing
access region or may include one or more self-closing regions
separated by unsupported regions and/or may include transition
regions on the ends of the access port 330, if desired.
[0138] In yet another option, any of the access devices described
herein may be included in a system or kit including one or more
instruments for accessing a tissue structure or graft through the
access device. For example, the instrument may include a needle
(not shown) including a tip larger than openings through the bands
350 of the access port 330. The tip of the needle may be configured
to facilitate passing the needle between the bands 350, e.g., to
separate the struts 352, connectors, 354, and/or other features.
For example, the needle may include at least one of a coating, a
surface treatment, and the like to facilitate passing the needle
between the support elements. In addition, the tip may be beveled
or tapered, i.e., including a beveled shape, to facilitate
inserting the needle through the openings in the bands 350.
Optionally, the bands 350 may be configured to facilitate inserting
the needle therethrough, e.g., by including tapered or rounded
edges on the struts 352, connectors 354, and/or other features.
[0139] In addition or alternatively, the needle may include one or
more features for limiting the depth of penetration of the tip
through the access port 330. For example, the needle may include a
bumper (not shown) spaced apart a predetermined distance from the
tip to prevent over-penetration of the needle through the access
port 330. In an exemplary embodiment, the bumper may be an annular
ridge or other feature (not shown) attached around or formed around
the needle at a predetermined distance from the tip.
[0140] Turning to FIGS. 15-17C, yet another embodiment of an access
port 430 is shown that is integrally formed on a tubular structure,
such as a tubular graft 410, e.g., formed from ePTFE or other
material. Generally, the access port 430 includes a port body 432,
a plurality of bands 450, and a fabric covering 460, similar to the
previous embodiments. The port body 432 and bands 450 may be formed
similar to the methods described above, e.g., such that the bands
450 surround or are embedded in the material of the port body 432,
and compress the material laterally and/or radially inwardly to
close an opening created through the port body 432. The port body
432 may be formed as a tubular body, e.g., before or after
attaching the bands 450, and then the port body 432 may be split,
e.g., as described above. The side edges (not shown) of the port
body 432 may be separated and the access port 430 positioned around
the tubular graft 410. Alternatively, the port body 432 may not be
split, and the access port 430 may simply be directed over one end
of the graft 410 to a desired location in an enclosed tubular
configuration (not shown).
[0141] Optionally, in any of the embodiments herein, the port body
may be formed from bioabsorbable material, e.g., PLA, PGA, SIS, and
the like. In this alternative, once the access port is implanted
within a patient's body, e.g., around or otherwise to an existing
tissue structure, the bioabsorbable material may be absorbed over
time and/or replaced with connective tissue. Thus, the
non-bioabsorbable components of the access port, e.g., the bands or
other resilient support elements, may remain indefinitely within
the patient's body to bias the tissue structure to self-seal after
one or more instruments are inserted through the bands or support
elements. Thus, the bands or support elements may provide or
enhance an elasticity of the tissue structure to accommodate access
therethrough.
[0142] In a further alternative, the bands or support elements
(such as any of those described herein) may be implanted without
being embedded within a base material. For example, the bands or
support elements may be applied around a tubular structure or to a
surface of an organ or other tissue structure (not shown).
Optionally, the bands or support elements may be coated or
otherwise provided with agents that enhance tissue ingrowth. Thus,
over time, tissue may grow into and/or around the struts or other
elements of the bands or support elements, thereby integrating the
bands or support elements into the tissue. Once so integrated, the
bands or support elements may provide self-sealing access sites,
similar to other embodiments herein.
[0143] Turning to FIGS. 24A-24C, another embodiment of an access
port 630 is shown that includes a plurality of annular bands 632
that are at least partially overlapping one another, e.g., such
that bands 632 define frustoconical shapes. Each band 632 may be
formed from one or more sheets of flexible base material including
a plurality of elastic bands or other support elements therein (not
shown), similar to other embodiments herein. Alternatively, each
band 632 may include a solid panel embedded within flexible base
material (also not shown). The support elements may be formed from
materials similar to other elements herein, e.g., Nitinol or other
superelastic metal, stainless steel, cobalt chromium, or other
metal.
[0144] As best seen in FIGS. 24B and 24C, each band 632 includes a
plurality of panels or sheets 644 attached together, e.g., to
define an enclosed tubular shape, or an open configuration that may
be wrapped around a tubular structure 610, such as a graft and the
like. For example the sheets 644 may be partially overlapped around
a periphery of each bands 632 and attached together, e.g., by
bonding with adhesive, suturing, and the like. Alternatively, the
sheets 644 may be provided separately and attached to the tubular
structure 610 one or more at a time, e.g., by attaching a first
sheet 644 and then attaching successive sheets 644 that partially
overlap one or more sheets 644 already attached to the tubular
structure 610.
[0145] Turning to FIGS. 25A and 25B, in an alternative embodiment,
an access port or device 730 may be provided that includes a
plurality of overlapping panels 750 embedded within flexible base
or substrate material 732, which may be constructed from materials
similar to any of the other embodiments herein. As shown, the
panels 750 may include edges 752 that overlap adjacent panels,
e.g., in a longitudinal direction (as shown in FIG. 25A) and/or
circumferential direction (as shown in FIG. 25B) such that the
edges 752 may be separated to provide a passage to accommodate an
instrument therethrough (not shown), as described further
below.
[0146] For example, in the example shown in FIG. 25B, an annular
band of panels 750 is provided that includes four panels whose side
edges 752a partially overlap one another. Further, in the example
shown in FIG. 25A, four annular bands of panels 750 are provided
along the length of the access port 730 whose end edges 752b
overlap one another in a frustoconical configuration. It will be
appreciated that additional or fewer panels 750 (than the four
shown) may be provided to define each band and/or that additional
or fewer bands may be provided along the length of the access port
740, as desired.
[0147] Similar to other embodiments herein, the access port 730 may
be provided as a separate tubular body such that the access port
730 may be attached to a tubular body 710, e.g., a tubular graft or
a tubular structure in situ, such as a blood vessel, fistula, or
implanted graft. Alternatively, the access port 730 may be provided
as a cuff or patch (not shown), e.g., including side edges
extending between ends of the access port 730. For example, the
access port 730 may have a "C" shaped cross-section or may have a
substantially flat or curved shape, if desired, similar to other
embodiment herein. The panels 750 may be provided around the entire
periphery of the cuff or patch or only partially between the side
edges and/or partially along the length of the cuff or patch, as
desired. In a further alternative, the panels 750 may be integrally
formed into a wall of a tubular structure, such as a tubular graft
(not shown).
[0148] The panels 750 and/or the base material 732 may be
sufficiently flexible such that the panels 750 may be separated
partially from one another during use. For example, if an
instrument, e.g., a needle and the like (not shown) were penetrated
into the access port 730, it may encounter one of the panels 750
and may move along the panel 750 until it encounters the overlapped
edges 752 of that panel 750 and an adjacent panel. Inward force of
the instrument may cause the overlapped edges 752 to separate
partially, e.g., by directing the panel 750 inwardly relative to
the adjacent panel. Thus, the instrument may pass freely between
the overlapped edges 752 and through the base material 732, e.g.,
into the underlying tubular body 710. Once the instrument (or other
device used with the instrument) is removed, the panels 750 may
resiliently return towards their original overlapped configuration,
thereby closing and/or substantially sealing the passage created
through the access port 730. In addition, as shown, existing
pressure within the tubular body 710 may also press outwardly,
thereby biasing the panels 750 to return outwardly to enhance the
seal created.
[0149] Turning to FIG. 1A, an exemplary embodiment of a graft 10 is
shown that includes two access ports 30, which may be any of the
embodiments herein. The graft 10 may be formed from synthetic or
biological material for vascular grafts, e.g., ePTFE, and the like,
and the access ports 30 may be integrally formed or attached to the
wall of the graft 10 at one or more desired locations, e.g., to
allow repeated access during hemodialysis and/or other procedures.
The graft 10 includes first and second ends 12, 14, e.g., for
attaching or otherwise integrating the graft 10 with the existing
vasculature of a patient. As shown, the first end 12 includes a
tapered or beveled shape, e.g., to allow the first end 12 to be
inserted into the lumen of an existing vessel and/or otherwise
attached thereto, e.g., by suturing. The second end 14 includes a
sutureless anastomotic coupler, shown in more detail in FIGS. 7A
and 7B. It will be appreciated that one or both ends of the graft
10 may include any of the couplers or features described
herein.
[0150] For example, turning to FIGS. 7A and 7B, an anastomotic flow
coupler 70 may be provided on one or both ends of a graft 10, e.g.,
to facilitate rapid, optionally sutureless, anastomosis, cause less
injury, and/or provide a smoother transition from graft to the in
situ vessel 90. The coupler 70 may include a highly elastic
structure 72 that forms a flared distal end incorporated within the
substrate material of the graft 10. For example, the coupler 70 may
include a skeleton or other structure 72, such as a stent-like
structure, e.g., including substantially straight struts
alternately coupled by curved connectors, and fabricated using
similar materials and/or processes as the CEB 50, described
elsewhere herein.
[0151] The elastic structure 72 may be embedded in the material of
the graft 10 or may be attached to an outer or inner surface of the
graft 10, e.g., by bonding with adhesive, fusing, sonic welding,
and the like. At least a portion of the coupler 70, e.g., the
flared rim 74, may be covered with fabric or other material, e.g.,
to enhance tissue ingrowth, or alternatively, the elastic structure
72 may remain exposed. Optionally, the flared rim 74 may have
sufficient length to provide a saddle or other shape that may be
attached to the vessel 90. The flared rim 74 may be resiliently
compressible, e.g., to engage the vessel wall 90 to enhance
remodeling of the vessel 90, if desired, similar to other
embodiments herein. In addition or alternatively, the flared rim 74
or the elastic structure 72 may provide a self-closing access
region, similar to other embodiments herein.
[0152] The coupler 70 may be inserted into the native vessel either
surgically or percutaneously. For example, a small incision may be
created in the vessel wall 90, e.g., less than the diameter of the
flared end of the coupler 70, and the flared end of the coupler 70
may inserted through the incision into the lumen. In an exemplary
embodiment, the coupler 70 may be sheathed or otherwise
constrained, e.g., within a sheath or catheter, to a diameter
smaller than the incision, and inserted through the opening and
into the lumen. The coupler 70 may then be released, e.g., by
deploying the coupler 70 from the sheath such that the flared end
resiliently returns to its flared shape, and the graft 10 may be
pulled back until the coupler 70 is opposed firmly against the
vessel wall 90. Intravascular pressure may further compress the
flared rim of the coupler 70 against the vessel wall 90, e.g., to
facilitate achieving hemostasis without requiring sutures or other
connectors. Optionally, the coupler 70 may also be attached to the
vessel 90, e.g., by suturing, bonding with adhesive, and the like,
if desired.
[0153] Alternatively, the coupler 70 may be plastically deformable
rather than self-expanding. For example, the support structure 72
may be formed from plastically deformable material, e.g., stainless
steel or other metal, plastic, or composite materials, that may be
provided initially substantially straight. Once the coupler 70 has
been inserted into an incision in the vessel wall 90, a balloon or
other expandable device (not shown), may be introduced into the
coupler 70 and/or vessel 90 and expanded to deform the support
structure 72 into a desired shape transitioning from the graft 10
to the vessel 90.
[0154] Turning to FIGS. 8A and 8B, an exemplary Flow Conduit (FC)
80 is shown that may be integrated as part of one or both ends of a
graft. The FC 80 may provide an anastomotic and/or
anti-thrombogenic structure, and is described further in the
applications incorporated by reference herein. Although the coupler
70 of FIGS. 7A and 7B and FC 80 of FIGS. 8A and 8B are shown
substantially orthogonal to the central axis of the graft, it will
be appreciated that the angle of the junction to the vessel 90 may
be less than ninety degrees (90.degree.), e.g., between about ten
and fifty degrees (10-50.degree.), which may create better flow
and/or other transition from the graft to the native vessel.
[0155] Turning to FIG. 21, yet another embodiment of a flow coupler
170 is shown that may be provided on one (or each) end 114 of a
graft 110 (which may or may not include access port(s) described
elsewhere herein, not shown). In this embodiment, the coupler 170
may include a flexible tubular material 172 having an elastic
structure 180 embedded or otherwise attached thereto. The tubular
material 172 may include fabric or other material that promotes
tissue ingrowth, e.g., polyester, ePTFE (with IND between about
50-150 .mu.m), and the like. The elastic structure 180 may include
one or more bands or mesh of elastic or superelastic material,
e.g., Nitinol, similar to the CEB 50 described above, which may be
embedded in the tubular material 172 and/or may be attached to the
inner or outer surface of the tubular material 172, e.g., by one or
more of suturing, bonding with adhesives, fusing, sonic welding,
and the like.
[0156] Optionally, as shown, the coupler 170 may include a collar
190, e.g., surrounding the tubular material 172 immediately
adjacent to the end 114 of the graft 110 or elsewhere along the
length of the coupler 170. The collar 190 may be shaped to be
received around a portion of the outer wall of the vessel 90 or
within the lumen of the vessel 90. The collar 190 may stabilize or
otherwise secure the coupler 170 relative to the vessel 90, and,
optionally, may be further secured to the vessel 90, e.g., by
suturing, bonding with adhesive, and the like, if desired.
[0157] The coupler 170 may have a substantially uniform diameter
similar to the graft 110 or may taper or otherwise transition to a
different diameter or cross-section, as desired, to provide a
desired flow pattern from the graft 110 into the vessel 90, e.g.,
to reduce thrombosis and/or intimal hyperplasia. The coupler 170
may be sufficiently flexible to accommodate bending without
substantial risk of kinking or buckling, e.g., allowing the coupler
170 to bend up to ninety degrees (90.degree.) to transition from
the graft 110 to the vessel 90 while providing a substantially
smooth interior lumen.
[0158] The elastic structure 180 may simply support the tubular
structure 172 or may bias the tubular structure 172 to a desired
diameter and/or shape. For example, as shown in FIG. 22, the
elastic structure 180' may bias the tubular structure 172' to a
bulbous shape, e.g., defining a relatively large diameter region
between the end 114' of the graft 110' and the tip 174' of the
coupler 170.' Alternatively, the elastic structure 180' may bias
the entire coupler 170' to a diameter larger than the diameter of
the vessel 90, e.g., to remodel the vessel 90 to a larger diameter
or desired shape.
[0159] In addition or alternatively, as shown in FIG. 23, a graft
110'' may be provided that includes a flow coupler 170'' on one end
114'' thereof that is biased to a helical or spiral shape. The
coupler 170'' may be sufficiently flexible to adopt any shape into
which it is placed yet may be biased to return towards the helical
shape to provide a desired flow characteristic through the coupler
170'' after implantation.
[0160] Exemplary embodiments of the present invention are described
above. Those skilled in the art will recognize that many
embodiments are possible within the scope of the invention. Other
variations, modifications, and combinations of the various
components and methods described herein can certainly be made and
still fall within the scope of the invention. For example, any of
the devices described herein may be combined with any of the
delivery systems and methods also described herein.
[0161] While embodiments of the present invention have been shown
and described, various modifications may be made without departing
from the scope of the present invention. The invention, therefore,
should not be limited, except to the following claims, and their
equivalents.
* * * * *